1. Field of the Invention
The present invention relates to a braking device, and particularly to a spool brake device for a dual-bearing reel, which is rotatably supported by a reel unit of the dual-bearing reel and is configured to electrically brake a spool for winding a fishing line thereabout.
2. Background Art
The well-known spool brake device for dual-bearing reel is normally configured to electrically brake a spool and includes power generating mechanism, which is formed by a coil and a magnet between a spool and reel unit. The well-known spool brake device is configured to electrically control the power generating mechanism for braking force during casting a fishing rod.
Japan Laid-open Patent Application Publication No. JP-A-2009-159847 describes an example of the well-known spool brake device including a magnet, a coil, a tension detection unit, and, a control mechanism. The magnet is disposed in the spool. The coil is disposed in the reel unit. The tension detection unit is configured to detect tension acting on a fishing line. The control mechanism is configured to determine a braking starting timing based on a detected tension and control electricity flowing through the coil. The well-known spool brake device for a dual-bearing reel is configured to detect variation in tension since starting of casting and start executing a predetermined control when tension becomes less than or equal to a predetermined value. Specifically, the well-known spool brake device is configured to execute a digital switching control for a switching element for regulating braking force to be target braking force expressed by a gradually decreasing duty cycle as a digital value.
In the aforementioned well-known spool brake device, the duty cycle is considered as braking force. Therefore, when electromotive force of the coil varies due to variation in size and attachment position of the magnet and the coil, current values vary even if a switching control is executed at the duty ratio set as the target braking force. This can destabilize the braking force.
It is an advantage of the present invention to reliably apply stable braking force to a spool even when electromotive force of a coil varies.